Data Communication and Object Localization Using Inductive Coupling

ABSTRACT

An apparatus and method are disclosed for a software and hardware configuration that uses inductive coupling to allow a physical object to determine information describing another physical object. An inductor capacitor circuit acts as a transmitter as well as a receiver of inductive field. A voltage signal provided to an inductor in an object causes the inductor to generate inductive field received by another inductor in a second object. An object receiving inductive field from another object analyzes the inductive field to receive arbitrary data, including but not limited to data that can allow the receiving object to determine the identity of the object transmitting the inductive field. The object receiving the inductive field can also determine the distance between the receiving object and the transmitting object based on the strength of a signal generated by the inductive field.

CROSS REFERENCES TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.61/254,324, filed Oct. 23, 2009, which is incorporated by reference inits entirety.

BACKGROUND

1. Field of Art

The disclosure generally relates to the field of electronics,particularly in the field of computing interaction.

2. Description of Art

A variety of wireless communication systems have been devised to solve ahost of needs. However, no such schemes combine resistance to opticalnoise and the ability to localize different faces of physical objectsdown to centimeter resolution. Most systems are based on infrared lightmodulation or other higher frequency radio communication. Infrared is inparticular vulnerable to interference from other light sources,particularly the sun. Higher frequency radio systems require sensitiveantenna design and entail a great deal of labor to properly design andimplement. These solutions are thus relatively high cost. These systemstypically radiate signals fairly evenly in three-dimensional space,making it difficult to determine which face of a transmitting object isnear another sensing object. Further, sonic or ultrasonic solutions areparticularly vulnerable to multi-path distortions and are expensivesolutions, requiring more hardware (speaker, microphone) and generallymore complex encoding and decoding algorithms.

SUMMARY

Apparatus and methods allow wireless communication between two objectsbased on inductive coupling. A first inductor coupled to a first objectgenerates an inductive field in response to a transmit signal providedto the inductor. A second inductor coupled to a second object generatesa signal responsive to the inductive field generated by the firstinductor. An analog to digital convertor is coupled to the secondinductor to receive the signal generated by the first inductor andconvert it to a digital signal output. The output of the analog todigital convertor is processed by a processor coupled to the analog todigital convertor. The processor converts the digital signal output to avalue indicative of a distance between the first physical object and thesecond physical object based on the strength of the received signal. Thetransmit signal can also can also encode arbitrary data, which theprocessor can interpret and act upon.

Another embodiment allows wireless communication between two objectsbased on inductive coupling. A first inductor coupled to a first objectgenerates an inductive field in response to a transmit signal providedto the inductor. The transmit signal can encode an arbitrary signal, forexample, a data value or any information. A second inductor coupled to asecond object generates a signal responsive to the inductive fieldgenerated by the first inductor. A comparator compares the signalgenerated by the second inductor with a threshold voltage signal. In anembodiment the comparator can be implemented using an op-amp(operational amplifier). A first input of the comparator is coupled tothe second inductor and a second input of the comparator is coupled tothe threshold voltage signal. The comparator output comprises a pulse ora sequence of pulses. A processor is coupled to the output of thecomparator, and is configured to convert the comparator output to avalue indicative of a distance between the first physical object and thesecond physical object based on the number of pulses in the sequence ofpulses. The sequence of pulses can also encode arbitrary data. Forexample, the data may identify the ID of the first object. The processorcan decode and act upon this data.

Another embodiment allows wireless communication between two objectsbased on inductive coupling. A first inductor coupled to a first objectgenerates an inductive field in response to a transmit signal providedto the inductor. A second inductor coupled to a second object generatesa signal responsive to the inductive field generated by the firstinductor. A processor is coupled to the second inductor. The processoris configured to convert the signal generated by the second inductor toa value indicative of a distance between the first physical object andthe second physical object. The transmit signal can also encodearbitrary data, which the processor can interpret and act upon.

Another embodiment allows wireless communication between two objectsbased on inductive coupling. A first inductor coupled to a first objectgenerates an inductive field in response to a transmit signal providedto the inductor. A second inductor coupled to a second object generatesa signal responsive to the inductive field generated by the firstinductor. A gain stage is coupled to the second inductor. The gain stageis coupled to a processor, directly or via a transistor,field-effect-transistor (FET), or comparator. The processor isconfigured to convert the signal generated by the gain stage to a valueindicative of a distance between the first physical object and thesecond physical object. The transmit signal can also encode arbitrarydata, which the processor can interpret and act upon via the gain stage.

A circuit allows transmitting and receiving signal across two physicalobjects via inductive coupling. The circuit comprises a first inductorcoupled in parallel to a capacitor to form an inductor-capacitor pair. Afirst end of the inductor-capacitor pair is connected to a groundconnection. A transmit signal is connected to a second end of theinductor-capacitor pair. The transmit signal is a varying voltage signalcausing the inductor to generate an inductive field. The first end ofthe inductor-capacitor pair is coupled to a circuit component to provideinput to the circuit component. The input to the circuit componentcomprises a signal generated by the inductor responsive to an inductivefield impinging on the inductor.

BRIEF DESCRIPTION OF DRAWINGS

The disclosed embodiments have other advantages and features which willbe more readily apparent from the detailed description, the appendedclaims, and the accompanying figures (or drawings). A brief introductionof the figures is below.

Figure (or FIG. 1 illustrates one embodiment of a perspective view of atop-down diagram of physical devices configurable for communicationbetween each other.

FIG. 2 illustrates one embodiment of a communication elementsconfiguration for a transmitting sensor and receiving sensor.

FIG. 3 illustrates one embodiment of a communication element of aphysical object.

FIG. 4 illustrates one embodiment of an alternate layout a communicationelements configuration for a transmitting and receiving sensor.

FIG. 5 illustrates one embodiment of a three dimensional representationof communicating devices, e.g., as shown in FIG. 1.

FIGS. 6( a-b) illustrate other embodiments of a three dimensionalrepresentation of communication devices, e.g., as shown in FIGS. 1 and5.

FIG. 7 illustrates one embodiment of a circuit that implements acommunication element shown in FIG. 3.

FIG. 8 illustrates another embodiment of a circuit that implements acommunication element shown in FIG. 3.

FIG. 9 illustrates a third embodiment of a circuit that implements acommunication element shown in FIG. 3.

FIG. 10 illustrates the various embodiments with different orientationsof the inductor with respect to a circuit board on which the inductor isinstalled.

FIG. 11 illustrates non-contiguous active areas in horizontally orientedinductors, in accordance with an embodiment.

FIG. 12 illustrates the impact of varying the distance between theinductors of two objects on the signal generated by the receivinginductor, in accordance with an embodiment.

The Figures (FIGS.) and the following description relate to preferredembodiments by way of illustration only. It should be noted that fromthe following discussion, alternative embodiments of the structures andmethods disclosed herein will be readily recognized as viablealternatives that may be employed without departing from the principlesof what is claimed.

DETAILED DESCRIPTION

Reference will now be made in detail to several embodiments, examples ofwhich are illustrated in the accompanying figures. It is noted thatwherever practicable similar or like reference numbers may be used inthe figures and may indicate similar or like functionality. The figuresdepict embodiments of the disclosed system (or method) for purposes ofillustration only. One skilled in the art will readily recognize fromthe following description that alternative embodiments of the structuresand methods illustrated herein may be employed without departing fromthe principles described herein.

Configuration Overview

One embodiment of a disclosed system, method and computer readablestorage medium that includes a software and hardware configuration thatincludes near-field data communication and object localization.Referring to Figure (FIG. 1 there is shown a system 10 of physicalobjects. The physical objects include a first physical object 12 a and asecond physical object 12 b (generally 12). Each physical object 12 a,12 b includes at least one communication element 14. Here, theillustrated configuration includes four (4) communication element 14a(1)-(4), 14 b(1)-(4) (generally 14) per physical object 12 a, 12 b.Each communication element 14 of a physical object, e.g., 12 a iscapable of wirelessly communicating with another communication element14 of the other physical object, e.g., 12 b. In the illustrativeexample, the communication comprises one or more messages 16. It isnoted that although FIG. 1 depicts four communication elements 14 perphysical object 12 a, 12 b, this is for illustration purposes only andthat each object 12 a, 12 b could have any number of communicationelements 14.

Each communication element 14 a of the first physical object 12 a iscapable of wireless communication with any other communication element14 b of the second physical object 12 b, provided they are sufficientlyclose to one another. The communication is established using inductivecoupling as further described below. The message 16 from onecommunication element, e.g., 14 a, to another communication element,e.g., 14 b, can contain arbitrary data, which a computing unit in object16 can either interpret in the context of a software application, ortransmit via any means to another destination for further processing.

It is noted that there are no specific limits on the size of the objects12 depicted, nor on the size of the communication elements 14 depicted,nor on the distance that a message 16 can be successfully transmitted.The distance just mentioned must be near enough to support inductivecoupling as described below. This distance varies with the physicalproperties of the communication elements 14 as described below.

In one embodiment the physical objects 12 can be made of any materialthat does not overly interfere with inductive coupling as describedbelow. Examples of acceptable materials include, but are not limited, toplastic, fiberglass, glass, and wood. The communication elements 14include a coil of conducting material, such as (but not limited to),copper, iron, and gold. The coil is also known as an inductor, and isfurther illustrated and described with respect to FIG. 2. Thecommunication elements also include other components, as furtherdescribed below.

Example Communication Configuration

FIG. 2 illustrates one embodiment of a communication element 14configuration for a transmitting sensor and receiving sensor. Theconfiguration as illustrated may be referenced as a system 20. Thesystem 20 is configured to include inductive coupling. In the system 20,a voltage signal 28 can be placed across an inductor 22 that can inducea voltage 26 in another nearby inductor 22, because the signal voltage28 placed across the transmitting inductor creates a field 24 that cancouple into the receiving inductor. By placing and removing anoscillating signal voltage 28 across a transmitting inductor in apattern, messages of arbitrary data are created that can be received andinterpreted by the receiving inductor. The presence or absence of asignal can be interpreted according to the specific application.

Turning to FIG. 3, it illustrates one embodiment of a communicationelement 14 of a physical object. In particular, the figure illustratesone embodiment of a circuit diagram depicting the subcomponents of thecommunication element 14. The circuit includes an inductor 22, aninductor-capacitor (LC) circuit 34, a transmit input 30 and a receiveinput 32.

Operationally, a varying voltage signal can be placed across thetransmit input 30. The LC circuit 34 resonates and creates a field ifthe transmit input contains energy at its resonant frequency, accordingto a formula:

$f = \frac{1}{2\pi \sqrt{LC}}$

It is noted that values of the inductor 22 and capacitor in the LCcircuit 34 can be selected to resonate at a chosen frequency. Further, afield created at the same or similar frequency impinging upon thecircuit 34 will induce a voltage on the LC circuit 34, causing it toproduce a voltage, which can be sensed and interpreted on receive input32. In this way, the communication element 14 can be used to bothtransmit and receive messages wirelessly, e.g., the message 16.

FIG. 4 illustrates one embodiment of an alternate layout for acommunication elements configuration for a transmitting and receivingsensor. This configuration is an alternate configuration for the system20. Here, the inductors 22 can be placed face-to-face, as shown in FIG.4, or in any of a variety of orientations with respect to one another.Functionally, the system 20 can be configured for operation inorientations shown in FIG. 4, as well as in other spatial orientationsusing the components described.

FIG. 5 illustrates one embodiment of a three dimensional representationof communicating devices, e.g., as shown in the system 10 configurationof FIG. 1. As previously noted, the first physical object 12 a and thesecond physical object 12 b each include one or more respectivecommunication elements 14 a, 14 b that transmit messages 16 embodied ascommunication signals 16. The messages 16 can be successfullytransmitted when the communication elements 12 a, 12 b of eachrespective physical object 12 a, 12 b are placed facing one another. Forexample, messages 16 are passed as a communication signal when a firstcommunication element 14 a(1) of the first physical object 12 a faces inclose proximity a first communication element 14 b(1) of the secondphysical object 12 b. It is noted that the messages 16 passed viacommunication signals between the communication elements 14 a(1), 14b(1) can occur either when the physical objects 12 a, 12 b are in thesame plane as well as when they are not co-planar, but are sufficientlyclose to one another along any axis. FIG. 5 illustrates two physicalobjects adjacent to each other along the x-y plane of a Cartesiancoordinate system. The objects themselves are placed in the x-y planei.e., horizontally.

FIG. 6( a) illustrates another embodiment of a three dimensionalrepresentation of communication devices, e.g., as shown in FIGS. 1 and5. In this configuration the physical objects 12 a, 12 b, 12 c includecommunication elements 14 that communicate signals 16. Note that thecommunication elements 14, as described above, can successfully transmitsignals 16 along any spatial axis. In this case, the objects 12 can bedirectly on top of one another and signals 16 can be successfullytransmitted. Also note that the configurations disclosed apply tosystems 10 with any plurality of objects 12 and communication elements14. As illustrated in FIG. 6( a), each object is placed in an x-y planeof a Cartesian coordinate system (horizontally) but multiple objectsaligned along a z-axis. FIG. 5 illustrates placing the objects adjacentto each other in the x-y plane and FIG. 6( a) illustrates placing oneobject on top of the other. However, the communication between theobjects functions correctly for other alignments as well. For example,FIG. 6( b) illustrates communication between the objects when they arein planes parallel to each other but at a position which is not directlyvertical with respect to each other but at an angle. Similarly, thecommunication between the objects functions even if one object is heldat an angle with respect to the other object (such that the planes ofthe two objects are not parallel to each other).

FIG. 10 shows three different embodiments illustrating three differentways in which the inductors 22 can be oriented with respect to oneanother in physical space. In FIG. 10(A) and (B), the inductors areoriented in a plane, same as that of the plane of the circuit board(“horizontal orientation”). In FIG. 10(C), the inductor is orientedperpendicular to the circuit board (“vertical orientation”). Based onthe characteristics of the field, the vertical orientation ensures thatthe communication elements will successfully transmit with one anotherin a contiguous spatial area in the plane of the circuit board.

FIG. 11 illustrates how horizontally oriented inductors can exhibitnon-contiguous areas of successful communication in the plane of thecircuit board. In many use cases, especially those involving ahuman-operated device, successful communication in non-contiguous areasin the plane of the circuit board can be a source of confusion for theuser. For example, in a toy allowing user to place objects adjacent toeach other, a user may be confused if two objects indicate they arealigned even if they are not. For example, a game involving physicalplacement of such objects may indicate successful completion based on anincorrect alignment of objects.

The system 10 of communication elements 14 can be used to transmitarbitrary data, for example, as shown in FIGS. 5 and 6. The distance atwhich such communication occurs can be made small (for example, 1centimeter (cm)). This allows elimination of interference that could becaused by objects that are at a distance greater than a threshold value.The distance at which communication occurs can be controlled bycontrolling various parameters related to the inductive field. Theseinclude, an amount of current flowing through the transmitting inductor22, a number and diameter of coils in inductor 22, the internalimpedance of inductor 22, a material of the core of inductor 22, whetherinductor 22 has external shielding material surrounding it, and thelike. A mere presence of a signal element 16 (for example, as shown inFIGS. 5 and 6) can be used to determine location of objects, in terms ofwhich objects are next to one another, and which face of the objects arenext to one another. Further, the strength of the signal element 16, interms of its peak voltage 26, can be measured by receive input 32. Thestrength of the signal 16 can be translated into a specific distance,since the peak voltage induced by a transmitting communication element14 into a receiving communication element 14 is directly correlated withdistance between the two elements. This voltage can be measured by aprocessor using an analog-to-digital converter. This measurement allowsthe system to accurately determine exactly how far one object 12 is fromanother object 12. In this way, the system 10 can be used to determineobject location.

The disclosed configuration allows for a field 24 that radiates in threedimensions. Hence, objects can be detected and their location determinedproximate to each other within three-dimensions (e.g., an x-axis, y-axisand z-axis within a Cartesian coordinate system). Radiation of a field24 as described beneficially provides an additional layer of informationfor the physical objects with respect to their location relative to eachother, for example, in configurations in which the physical objects areplaced on top of one another the respective physical object candetermine that they are in a stack.

Referring now to the embodiment shown in FIG. 7, a circuit diagramprovides an example embodiment of communication element 14. Theseinclude the inductor 22, the LC circuit 34, a transmit input 30 and areceive input 32. This diagram shows more detail as to a possibleembodiment of signal transmit and receive functionality. In particular,note elements 70 (ADC/ADC1/ADC2), in which communication element 14 canmeasure, using and Analog-to-Digital Converter (“ADC”) 70, or similarsystem, the size of the voltage signal in order to estimate distancefrom another transmitting communication element 14. Note in the diagramthat this signal level may be measured at various points in the circuit,depending on the desired level of amplification of the received signalat the time of measurement. In this embodiment, a comparator 74sensitivity can be set with a threshold voltage 72 to tune thesensitivity of the circuit, which can also be used to estimate distancefrom another transmitting communication element 14.

Referring now to the embodiment shown in FIG. 8, a circuit diagramprovides an example embodiment of communication element 14. Theseinclude an inductor 22, an LC circuit 34, a transmit input 30 and areceive input 32. This diagram shows more detail as to a possibleembodiment of signal transmit and receive functionality. In particular,the circuit controls for variations in the input impedance of thetransmit signal and controls for general circuit noise. As shown in FIG.8, the op-amp 74(a) input 73(a) is connected to the signal generated bythe inductor 22 via a resistor 75(b) and an optional capacitor 34(b)connected serially. The op-amp 74(a) is further connected to a resistor75(a) and an optional capacitor 34(a) each connected in parallel withthe input of the op-amp and the output of the op-amp 74(a). The outputof the op-amp 74(a) can be input to analog-to-digital convertor ADC2 70.The output of the op-amp 74(a) is also connected via resistor 75(c) to atransistor 82 that outputs the signal RX 32. The signal TX 30 is inputto an op-amp 74(b) that provides feedback of its output to one of theinputs. The output of the op-amp 74(b) is connected via a capacitor 14to the inductor-capacitor pair formed by inductor 22 and capacitor 34.

Referring now to the embodiment shown in FIG. 9, a circuit diagramprovides an example embodiment of communication element 14. Theseinclude an inductor 22, an LC circuit 34, a transmit input 30 and areceive input 32. This diagram shows more detail as to a possibleembodiment of signal transmit and receive functionality (severalelements shown in FIG. 9 are as illustrated in FIG. 8). In particular,the circuit controls for variations in the input impedance of thetransmit signal and controls for general circuit noise. Voltage bias inelement 96 allows detection of the full peak-to-peak voltage swing ofthe input receive signal, increasing sensitivity of the circuit.Inclusion of the comparator 92 allows for control of receive sensitivityas well using comparator threshold 94, because a comparator can bedesigned to detect smaller signals than a simple transistor 82, as shownin FIG. 8.

It should be clear that elements in each of the circuits shown in FIGS.3 and 7 through 10 can be mixed and matched in a specific embodiment,and that these figures do not exhaustively list all circuits that areembodiments. The disclosed configurations also can be used to measuredistance from one element 14 to another element 14 in another fashionthat does not use an analog-to-digital converter.

Referring now to the invention shown in FIGS. 7,8 and 9, the closer atransmitting element inductor 22 is to a receiving element inductor 22,the greater the number of pulses that will be generated at point 32 inthe circuit. A transmitting element inductor 22, when excited by anincoming electrical pulse, induces a damped sinusoidal signal in thereceiving element inductor 22. The voltage level of each peak in theinduced damped sinusoidal signal increases as the transmitting inductor22 is brought closer to the receiving inductor 22. Since a pulse isproduced at point 32 in the circuit for every peak that passes a certainthreshold in the receiving element inductor 22, a nearby transmittinginductor 22 will cause more pulses at 32 than one that is farther away.

Given this behavior in the circuit, the system can count the number ofpulses within a certain time frame that are induced at point 32, andinfer the distance between the receiving element inductor 22 and thetransmitting element inductor 22.

Example Data Communication and Object Localization

Provided below are example protocols for data communication and/orobject localization for use with the system 10. In particular, threeexample schemas are further described below.

Scheme #1: Asynchronous Three Pulse Protocol

In a first embodiment of a scheme, a physical object 12 sends transmit amessage (as a communication signal) 16 on each communication element 14,transmissions are not synchronized with respect to any master schedule.Communication elements 14 are in receive (RX) mode if not being used fortransmit (TX). A TX consists of two “hits” at point 32 in the circuit,followed by a third hit. Each “hit” corresponds to an electrical pulseor set of pulses created in a receiving element 14 at point 32 by asignal induced in transmitting element 14. The time offset between thesecond and third hit encodes the identity of the object 12 and theidentity of the specific communication element 14. Similar schemes canuse a different number of hits per TX. The time difference between twoor more of the hits encodes identification information. Similarly, itwould be possible to encode the identity of the object 12 with the timedifference between a certain pair of hits, and the identity of thespecific communication element 14 with the time difference between adifferent pair of hits.

Described below is how physical object 12 interprets signals 16 from areceiving communication element 14 to determine the transmitting object12's identity and the identity of the specific transmittingcommunication element 14. The interpretation involves a simple statemachine that changes states based on the arrival time of incomingtransmission pulses. Two states are used.

RX State machine:

State “S1”: receiver is waiting to receive 1^(st) or 2nd signature hit

State “S2”: receiver is waiting to receive 3rd hit

State machine transition map:

BEGIN S1:

-   -   if receive pulse within specific pre-determined time offset (+/−        some margins of error) from previous hit, go to S2    -   else, go to S1 (all error cases go to S1)

S2:

-   -   if we receive a valid hit, send time offset information to        application software, go to S2    -   if we receive an invalid hit, go to S1

A valid hit is a signal received within any of a set of time intervals,plus or minus some margin of error. The set of time intervals can bestored or generated algorithmically. An invalid hit is a signal receivedbefore or after the predetermined length of time interval, outside themargin of error. For example, if the signal is received after a verylong period of time, the signal is not considered a part of the currentstate transition sequence. The application software executing on object12 or another associated computer system is configured to use the timeoffset measured in S3, to determine a particular object 12's identityand the identity of the specific transmitting communication element 14.This localization information can now be used and/or transmitted by theobject 12 for use in an application.

Scheme #2: Asynchronous Byte-Sending Strategy

A second embodiment of a scheme includes a protocol similar to apreviously describe protocol of scheme #1, except that the data isencoded differently. It does not involve an already-determined timeoffset to a particular object 12 and the identity of the specifictransmitting communication element 14. Rather, this information, alongwith any other information, can be encoded in the transmission signalitself. Each ping or bit corresponds to a hit created in a receivingelement 14 at point 32 by a pulse or hit initiated in transmittingelement 14.

Scheme #2:

HANDSHAKE (optional)

-   -   transmitter sends ping (1 bit)    -   receiver sends acknowledgment (ACK) ping (1 bit)

BYTE STREAM

-   -   transmitter sends bytestream (1 start bit (optional)+N data        bits)    -   error correction code (optional)

The bytestream encodes object 12's identity and the identity of thespecific transmitting communication element 14. In some cases it mayhelp for the objects 12 to exchange a “handshake”. There are many waysto encode such a handshake, but it may consist of a single hit beingtransmitted from transmitter to receiver, followed by a single hit beingtransmitted from receiver to transmitter. Error-correction based onchecksum or other forms of error-correction may also be used in thisscheme to verify that a received message is valid. In suchconfigurations, some form of acknowledgement by the receiver withpossible re-transmission in the case of invalid message receipt may beused.

Scheme #3: Synchronous Strategy

A third example scheme requires a master schedule shared by all objects12. A temporal sync among all objects is created upon initialization,and a time-slice is allocated for each object and each of its specifictransmitting communication elements 14. All objects 12 are aware of themaster time schedule: if the object 12 receive a hit at a certain timeon one of its communication elements 14, it can uniquely identify thetransmitting object 12 and specific communication element 14, since thereceiving object 12 is aware of when each other object 12 andcommunication element 14 should be hit-inducing signal.

Scheme #3:

-   -   During its assigned time slot, the object 12 will emit a        transmission pulse on each of its communication elements 14,        round-robin    -   If any object 12 receives a hit during one of these        transmissions, it compares the arrival time of that hit against        the master schedule        -   the master schedule will determine the identity of the            object 12 and specific communication element 14        -   the transmitting object 12 and communication element 14 is            now known to the receiving object 12, and can be used and/or            transmitted by the application

The above schemes serve as examples for use in object localization, butare not limited to the schemes listed above. Arbitrary data may betransmitted that can code for location or any other information in avariety of ways.

The advantages of the disclosed configurations include, withoutlimitation, its lower complexity and cost (e.g., only simple passiveand/or inexpensive components s are required to implement the solution)and its resistance to noise and interference (e.g., the communicationelement 14 can be tuned to operate at a frequency with very littlenatural or man-made interference). Further, the disclosed configurationsare resistive to interference with regard to physical material beingplaced between two communication elements 14. Thus, unlike othersolutions, the disclosed configuration can work through solid plastic orother materials, removing the need for unsightly and costly ‘windows’ orinfrared-transparent panels. Moreover, without such limiting factors thedisclosed configuration allows for the ability to determine distancebetween objects 12 and adding manipulation within three-dimensionswithout unsightly, heavy or expensive physical object structures.

In broad embodiment, a system is configured in which physical objects 12can be inexpensively instrumented for wireless communication, and inwhich said wireless communication can be used to localize objects withrespect to one another.

Some portions of this specification are presented in terms of algorithmsor symbolic representations of operations on data stored as bits orbinary digital signals within a machine memory (e.g., a computermemory). These algorithms or symbolic representations are examples oftechniques used by those of ordinary skill in the data processing artsto convey the substance of their work to others skilled in the art. Asused herein, an “algorithm” is a self-consistent sequence of operationsor similar processing leading to a desired result. In this context,algorithms and operations involve physical manipulation of physicalquantities. Typically, but not necessarily, such quantities may take theform of electrical, magnetic, or optical signals capable of beingstored, accessed, transferred, combined, compared, or otherwisemanipulated by a machine. It is convenient at times, principally forreasons of common usage, to refer to such signals using words such as“data,” “content,” “bits,” “values,” “elements,” “symbols,”“characters,” “terms,” “numbers,” “numerals,” or the like. These words,however, are merely convenient labels and are to be associated withappropriate physical quantities.

Unless specifically stated otherwise, discussions herein using wordssuch as “processing,” “computing,” “calculating,” “determining,”“presenting,” “displaying,” or the like may refer to actions orprocesses of a machine (e.g., a computer) that manipulates or transformsdata represented as physical (e.g., electronic, magnetic, or optical)quantities within one or more memories (e.g., volatile memory,non-volatile memory, or a combination thereof), registers, or othermachine components that receive, store, transmit, or displayinformation.

As used herein any reference to “one embodiment” or “an embodiment”means that a particular element, feature, structure, or characteristicdescribed in connection with the embodiment is included in at least oneembodiment. The appearances of the phrase “in one embodiment” in variousplaces in the specification are not necessarily all referring to thesame embodiment.

Some embodiments may be described using the expression “coupled” and“connected” along with their derivatives. For example, some embodimentsmay be described using the term “coupled” to indicate that two or moreelements are in direct physical or electrical contact. The term“coupled,” however, may also mean that two or more elements are not indirect contact with each other, but yet still co-operate or interactwith each other. The embodiments are not limited in this context.

As used herein, the terms “comprises,” “comprising,” “includes,”“including,” “has,” “having” or any other variation thereof, areintended to cover a non-exclusive inclusion. For example, a process,method, article, or apparatus that comprises a list of elements is notnecessarily limited to only those elements but may include otherelements not expressly listed or inherent to such process, method,article, or apparatus. Further, unless expressly stated to the contrary,“or” refers to an inclusive or and not to an exclusive or For example, acondition A or B is satisfied by any one of the following: A is true (orpresent) and B is false (or not present), A is false (or not present)and B is true (or present), and both A and B are true (or present).

In addition, use of the “a” or “an” are employed to describe elementsand components of the embodiments herein. This is done merely forconvenience and to give a general sense of the invention. Thisdescription should be read to include one or at least one and thesingular also includes the plural unless it is obvious that it is meantotherwise.

Upon reading this disclosure, those of skill in the art will appreciatestill additional alternative structural and functional designs for asystem and a process for data communication and object localizationusing inductive coupling through the disclosed principles herein. Thus,while particular embodiments and applications have been illustrated anddescribed, it is to be understood that the disclosed embodiments are notlimited to the precise construction and components disclosed herein.Various modifications, changes and variations, which will be apparent tothose skilled in the art, may be made in the arrangement, operation anddetails of the method and apparatus disclosed herein without departingfrom the spirit and scope defined in the appended claims.

1. An apparatus for wireless communication between two objects based oninductive coupling between the objects, the apparatus comprising: afirst inductor coupled to a first object, wherein the first inductorgenerates an inductive field responsive to a transmit signal; a secondinductor coupled to a second object, wherein the second inductorgenerates a signal responsive to the inductive field generated by thefirst inductor; an analog to digital convertor coupled to the secondgenerator to convert the signal generated by the second inductor to adigital signal output; and a processor coupled to the analog to digitalconvertor, wherein the processor is configured to convert the digitalsignal output to a value indicative of a distance between the firstphysical object and the second physical object.
 2. The apparatus ofclaim 1, wherein the transmit signal is a varying voltage signal.
 3. Theapparatus of claim 1, wherein the first inductor is further coupled to afirst capacitor in parallel to form a first inductor-capacitor pair andthe second inductor is further coupled to a second capacitor in parallelto form a second inductor-capacitor pair the first inductor-capacitorhas a resonant frequency within a first threshold value of a resonantfrequency of the second inductor-capacitor pair.
 4. The apparatus ofclaim 3, wherein the transmit signal includes a signal component at afrequency within a second threshold value of a resonant frequency of thefirst inductor-capacitor pair.
 5. The apparatus of claim 1, the firstinductor is physically placed at an angle perpendicular to a circuitboard within a threshold angle value, the circuit board comprising atleast one component electronically connected to the first inductor. 6.The apparatus of claim 1, wherein the first object and the second objectcomprise material that does not interfere with the inductive fieldgenerated by the first inductor and received by the second inductor. 7.The apparatus of claim 1, wherein the first object is placed on top ofthe second object to cause the inductive coupling between the firstinductor and the second inductor.
 8. The apparatus of claim 1, whereinthe first object is placed horizontally adjacent to the second object tocause the inductive coupling between the first inductor and the secondinductor.
 9. An apparatus for wireless communication between two objectsbased on inductive coupling between the objects, the apparatuscomprising: a first inductor coupled to a first object, wherein thefirst inductor generates an inductive field responsive to a transmitsignal; a second inductor coupled to a second object, wherein the secondinductor generates a signal responsive to the inductive field generatedby the first inductor; a comparator for comparing the signal generatedby the second inductor with a threshold voltage signal, wherein a firstinput of the comparator is coupled to the second inductor, a secondinput of the comparator is coupled to the threshold voltage signal, andthe comparator output comprises one or more pulses; and a processorcoupled to the output of the comparator, wherein the processor isconfigured to convert the comparator output to a value indicative of adistance between the first physical object and the second physicalobject based on the number of pulses in the comparator output.
 10. Theapparatus of claim 9, wherein a first value indicative of distancedetermined from a first number of pulses is higher than a second valueindicative of distance determined from a second number of pulses if thesecond number of pulses is higher than the first number of pulses. 11.The apparatus of claim 9, wherein the first inductor is further coupledto a first capacitor in parallel to form a first inductor-capacitor pairand the second inductor is further coupled to a second capacitor inparallel to form a second inductor-capacitor pair the firstinductor-capacitor has a resonant frequency within a first thresholdvalue of a resonant frequency of the second inductor-capacitor pair. 12.The apparatus of claim 11, wherein the transmit signal includes a signalcomponent at a frequency within a second threshold value of a resonantfrequency of the first inductor-capacitor pair.
 13. The apparatus ofclaim 9, the first inductor is physically placed at an angleperpendicular to a circuit board within a threshold angle value, thecircuit board comprising at least one component electronically connectedto the first inductor.
 14. An apparatus for wireless communicationbetween two physical objects based on inductive coupling between theobjects, the apparatus comprising: a first inductor coupled to a firstobject, wherein the first inductor generates an inductive fieldresponsive to a transmit signal; a second inductor coupled to a secondobject, wherein the second inductor generates a signal responsive to theinductive field generated by the first inductor; and a processor coupledto the second inductor, wherein the processor is configured to convertthe signal generated by the second inductor to a value indicative of adistance between the first physical object and the second physicalobject.
 15. The apparatus of claim 14, wherein the processor is coupledto the second inductor via a an analog to digital convertor, the analogto digital convertor converts the signal generated by the secondinductor to a digital signal output and the processor configured todetermine the value indicative of the distance based on the digitalsignal.
 16. The apparatus of claim 14, wherein the processor is coupledto the second inductor via a comparator coupled with the second inductorfor receiving the generated signal, wherein the comparator compares thegenerated signal with a fixed threshold signal, to output a set ofpulses.
 17. The apparatus of claim 14, wherein the first inductor isfurther coupled to a first capacitor in parallel to form a firstinductor-capacitor pair and the second inductor is further coupled to asecond capacitor in parallel to form a second inductor-capacitor pairthe first inductor-capacitor has a resonant frequency within a firstthreshold value of a resonant frequency of the second inductor-capacitorpair.
 18. The apparatus of claim 17, wherein the transmit signalincludes a signal component at a frequency within a second thresholdvalue of a resonant frequency of the first inductor-capacitor pair. 19.The apparatus of claim 14, wherein the first inductor is physicallyplaced at an angle perpendicular to a circuit board within a thresholdangle value, the circuit board comprising at least one componentelectronically connected to the first inductor.
 20. An apparatus forwireless communication between two physical objects based on inductivecoupling between the objects, the apparatus comprising: a first inductorcoupled to a first object, wherein the first inductor generates aninductive field responsive to a transmit signal, the transmit signalencoding a data value; a second inductor coupled to a second object,wherein the second inductor generates a signal responsive to theinductive field generated by the first inductor; and a processor coupledto the second inductor, wherein the processor is configured to processthe signal generated by the second inductor to decode the data valueencoded in the transmit signal.
 21. The apparatus of claim 20, whereinthe processor is coupled to the second inductor via a an analog todigital convertor, the analog to digital convertor for converting thegenerated signal to a digital signal output.
 22. The apparatus of claim20, wherein the processor is coupled to the second inductor via acomparator, wherein the comparator compares the generated signal with afixed threshold signal, to output a set of pulses.
 23. The apparatus ofclaim 20, wherein the first inductor is further coupled to a firstcapacitor in parallel to form a first inductor-capacitor pair and thesecond inductor is further coupled to a second capacitor in parallel toform a second inductor-capacitor pair the first inductor-capacitor has aresonant frequency within a first threshold value of a resonantfrequency of the second inductor-capacitor pair.
 24. The apparatus ofclaim 23, wherein the transmit signal includes a signal component at afrequency within a second threshold value of a resonant frequency of thefirst inductor-capacitor pair.
 25. The apparatus of claim 20, whereinthe first inductor is physically placed at an angle perpendicular to acircuit board within a threshold angle value, the circuit boardcomprising at least one component electronically connected to the firstinductor.
 26. A circuit for transmitting and receiving signal across twophysical objects via inductive coupling, the circuit comprising: a firstinductor coupled in parallel to a first capacitor to form aninductor-capacitor pair, a first end of the inductor-capacitor pairconnected to a ground connection; a transmit signal connected to asecond end of the inductor-capacitor pair, wherein the transmit signalis a varying voltage signal causing the inductor to generate aninductive field; and the first end of the inductor-capacitor paircoupled to a circuit component such that the first end provides input tothe circuit component, wherein the input to the circuit componentcomprises a signal generated by the inductor responsive to an inductivefield impinging on the inductor.
 27. The circuit of claim 26, whereinthe circuit component is an analog to digital convertor for generating adigital signal based on a strength of the signal generated by theinductor as a result of inductive field impinging on the inductor. 28.The circuit of claim 26, wherein the circuit component is a comparatorfor comparing the signal generated by the inductor with a thresholdsignal.
 29. The circuit of claim 28, wherein the comparator outputcomprises a sequence of pulses, the number of pulses based in part onthe strength of signal generated by the inductor.
 30. The circuit ofclaim 26, wherein a first input of the comparator is coupled to theinductor and a second input of the comparator is coupled to a thresholdvoltage.
 31. The circuit of claim 30, wherein the second input of thecomparator is coupled to the threshold voltage supply via a resistor.32. The circuit of claim 30, wherein the second input of the comparatoris coupled to the ground via a capacitor.
 33. The circuit of claim 26,further comprising a processor coupled to the circuit component forreceiving an output signal from the circuit component, wherein theprocessor is configured to determine a value indicative of a distancebetween the first physical object and the second physical object basedon the strength of the signal generated by the inductor.